In recent years, research has been conducted on radar-related technologies, such as forward collision warning systems that warn a driver of possible collision with a preceding vehicle or obstacle based on the measured speed of and distance to the preceding vehicle or obstacle, lane departure warning systems that warn a driver when the driver's own vehicle is leaving its lane, advanced emergency braking systems that enable safe driving by automatic deceleration, acceleration, and constant speed control based on driving situations, and adaptive cruise control systems.
Particularly, adaptive cruise control (ACC) systems and collision damage mitigation (CDM) systems have been successfully developed. ACC systems are equipped to detect a preceding vehicle to control the speed of a driver's vehicle to that of the preceding vehicle. CDM systems are equipped to warn a driver that the driver's own vehicle will collide with a preceding vehicle and to automatically actuate a brake. Such systems are currently being produced on an industrial scale.
In ACC and CDM systems, radars are employed to detect preceding vehicles and radar covers are mounted in front of the radars to protect the radars from the external environmental factors, such as moisture. Radars are also widely used for many applications, including weather monitoring and search, as well as in ships and airplanes due to their ability to clearly distinguish targets from surrounding geographical features and obstacles even at night and in foggy and rainy conditions.
There still remains a need for a radar cover that is mounted in front of a radar to perform its fundamental function to protect the radar equipment and through which signals from the radar are transmitted efficiently with reduced reflection loss.